SEOUL, S.Korea - South Korea knows of about 100 sites linked to North Korea's nuclear programme and has the capacity to strike them if an attack from the North is imminent, the defence minister said Monday.

"There are about 100 sites related to the nuclear' programme, Kim Tae-Young told legislators during a parliamentary audit of his ministry's work.

"We have a complete list of them," Yonhap news agency quoted him as saying.

Kim expressed confidence his forces could hit any of them "if it is absolutely clear a North Korean offensive is imminent."

Similar comments by Kim last month drew criticism from the North's official cabinet newspaper Minju Josun.

The communist North and capitalist South have remained technically at war since their 1950-53 conflict ended only in an armistice and not a peace treaty.

The North has conducted two atomic weapons tests since 2006.

Separately, the defence ministry said the North is thought to have 13 types of viruses and germs which can be used in biological weapons, as well as up to 5,000 tons of chemical weapons.

In a report to parliament, the ministry said the North has one of the world's largest stockpiles of chemical and biological weapons.

The list of diseases that could be caused by the biological weapons includes cholera, yellow fever, smallpox, eruptive typhus, typhoid fever and dysentery, it said.

The assertion that the North has chemical and biological weapons, in addition to its nuclear and conventional weaponry, is not new. But Monday's report gave more details of the alleged biological arsenal.

The International Crisis Group said in a report in June that the chemical weapons could be deliverable by artillery or missile to cause massive civilian casualties in South Korea.

The Brussels-based think-tank said the stockpile includes between 2,500-5,000 tons of mustard gas, phosgene, blood agents, sarin and persistent nerve agents.

The South's 655,000-strong military, backed up by 28,500 US troops, faces off against the North's 1.2-million-member armed forces.